Otto Michael
Biomol Concepts. 2013 Oct;4(5):533-7. doi: 10.1515/bmc-2013-0025.
Methicillin-resistant Staphylococcus aureus (MRSA) is the most frequent cause of hospital-associated morbidity and mortality. One reason why MRSA has remained a serious threat to public health is that new clones of MRSA constantly keep re-emerging. These new clones are better adapted to thrive in the hospital environment or even the community than their predecessors because they have developed increased and diversified antibiotic resistance and/or enhanced virulence. In addition, non-symptomatic colonization has been identified as a risk factor for subsequent MRSA infection; therefore, acquisition of factors promoting colonization has gained increased attention regarding the surge of MRSA outbreak clones. Two specific genes or genetic loci, namely sasX and the arginine catabolic mobile element (ACME), could recently be linked to the epidemiological success of MRSA clones, supporting the notion that colonization factors play a crucial role in MRSA outbreaks. SasX is a surface protein that enhances nasal colonization. ACME contains an arc arginine deiminase gene cluster promoting the survival of MRSA in the acidic skin environment, in addition to a polyamine resistance gene that deals with the increased production of toxic polyamines by the host that is prompted by arc. Notably, a better understanding of MRSA colonization on the molecular level may lead to eradication strategies based on vaccination or bacterial interference, with great promise to decrease MRSA infection rates.
耐甲氧西林金黄色葡萄球菌（MRSA）是医院相关发病和死亡的最常见原因。MRSA仍然对公共卫生构成严重威胁的一个原因是，新的MRSA克隆不断涌现。这些新克隆比其前身更能适应在医院环境甚至社区中生存，因为它们产生了更强且更具多样性的抗生素耐药性和/或增强了毒力。此外，无症状定植已被确定为后续MRSA感染的一个风险因素；因此，促进定植的因素的获得在MRSA暴发克隆激增方面受到了越来越多的关注。最近发现两个特定基因或基因位点，即sasX和精氨酸分解代谢移动元件（ACME），与MRSA克隆在流行病学上的成功有关，这支持了定植因素在MRSA暴发中起关键作用的观点。SasX是一种促进鼻腔定植的表面蛋白。除了一个应对宿主因arc诱导产生的有毒多胺增加的多胺抗性基因外，ACME还包含一个促进MRSA在酸性皮肤环境中生存的弧精氨酸脱亚氨酶基因簇。值得注意的是，在分子水平上更好地理解MRSA定植可能会带来基于疫苗接种或细菌干扰的根除策略，有望大幅降低MRSA感染率。
